Glomopay Frontend Interview Prep ​
Read my intro — background, experience, and what I've worked on.
Company Context ​
Glomopay is a fintech company building payment, investment, and KYC products. The role involves building checkout SDKs, merchant dashboards, and internal admin tools.
What HR Shared for Coding Round ​
- Fluent with React + TypeScript
- Clear idea for state management
- Unit tests
- SOLID principles
Tech Stack They Use ​
- React 19, Next.js, TypeScript
- State: Redux / Zustand / TanStack Query
- Styling: Tailwind CSS
- Testing: Jest (unit), Playwright/Cypress (E2E)
- Performance: Lighthouse, Core Web Vitals
Prep Notes (in notes/) ​
| # | File | Topic |
|---|---|---|
| 1 | 01-react-typescript.md | React + TypeScript patterns |
| 2 | 02-state-management.md | State management trade-offs |
| 3 | 03-solid-principles.md | SOLID principles in React |
| 4 | 04-unit-testing.md | Unit testing patterns |
| 5 | 05-performance.md | Performance optimization |
| 6 | 06-system-design.md | Frontend system design (checkout SDK, dashboards) |
| 7 | 07-behavioral-talking-points.md | What they value + how to frame answers |
| 8 | 08-checkout-customization-challenge.md | Checkout customization coding challenge |
General Frontend Concepts ​
88 advanced frontend concepts are in a separate directory (not Glomopay-specific): Frontend Concepts — see its own index for the full list.
Practice Projects ​
Checkout Flow (practice-checkout/) ​
A mini checkout flow that exercises all four coding round areas:
- React + TypeScript component composition
- State management with Context + useReducer
- Unit tests with Jest + React Testing Library
- SOLID architecture throughout
Checkout Customization (practice-customization/) ​
A form + live preview challenge covering:
- Form handling with dirty tracking and validation
- Derived state (isDirty, errors computed each render)
- Mock API with fetch/save
- useState for simple state shapes (contrast with useReducer above)
Quick Revision Checklist ​
- [ ] Can I explain discriminated unions and when to use them?
- [ ] Can I pick a state management tool and justify the trade-offs?
- [ ] Can I separate server state from client state?
- [ ] Can I name all 5 SOLID principles and show React examples?
- [ ] Can I write a test that tests behavior, not implementation?
- [ ] Can I explain Core Web Vitals (LCP, FID/INP, CLS)?
- [ ] Can I explain code splitting and lazy loading?
- [ ] Can I design a checkout SDK architecture?